SAITO twin cylinder FA-100T One cylinder cutting off - RC Groups
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Aug 10, 2005, 06:27 PM
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ROUTIER's Avatar

SAITO twin cylinder FA-100T One cylinder cutting off

Hello everybody. May be someone could find the solution and help me?
The Saito is fitted on a Nort Hamerican T6 and have been breaking with 1 fuel liter Then we have try to fly the T6 (maiden flight). In flight one cylinder stop to light and burn the fuel so power decrease a lot and we wher obliged to an emergency landing resulting in somes dammages on the landing gear and wings.
The Saito was driving a Master Airscrew 14x6, fuel 17% of synthétic oil and 5% nitromethane, T6 weight is at 5 Kg and an onboard glow power provide full power from back stick to 33% and 50% power from 33% to 50% from the stick position.
I have check the glow witch are goods.

Did any people know this engine and know how to set correctly this problem?
Last edited by ROUTIER; Aug 16, 2005 at 04:46 PM. Reason: correction
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Aug 11, 2005, 09:06 AM
S.A.D. member
ivanc's Avatar
Check the onboard glow driver - does it work properly, is the battery fully charged before the first flight. I'd also replace the glowplug in that cylinder just in case - even if it checks OK. I'd recommend using OS #F 4-stroke glowplugs. Keep in mind that if the onboard glow works properly and one of the plugs cools during flight, you need to bring the throttle stick back to less than 1/3, so that the glow driver fully energizes the plugs. Do it while the plane still has enough altitude - it will take several seconds for the cold glow plug to warm up and burn the excess fuel accumulated in it.

The engine also has separate needle valves - improper adjustment to one of them might cause a flame out to that cylinder. Make sure that both cylinders run slightly rich on the ground.
Aug 11, 2005, 05:08 PM
Registered User
ROUTIER's Avatar
Thanks for all thoses advices.
To day I have run the engine (on the ground) and burn again 1 liter without any problem.
I have changed the two glow (OS # F previous where SAITO #3). I changed also the airscrew witch was broken during last emmergency landing by a Master Airscrew 14x8.
I have also check the seting for the two carbs and the engine was runing steady at full power at 8200 rpm and 2600 rpm at idle. At the end of this run the engine was runing a litle bit faster at 8400 rpm and the both cylinder where runing perfectly without any flame out. May be this adding breaking and the two new glow could save the problem !
Last edited by ROUTIER; Aug 11, 2005 at 05:22 PM. Reason: minor corrections
Aug 11, 2005, 05:18 PM
S.A.D. member
ivanc's Avatar
I hope so! Have fun!!!
Aug 11, 2005, 08:15 PM
In Massive Debt
Also, that engine is never going to run well on that fuel. I would run powermaster 20/20. Just today at the field some pople were breaking in a YS 110, and it wouldnt transition smoothly, or idle smoothly, but after they realized they were using 5%nitro, and 16% synthetic fuel they quickly switched to 20/20, and it imporved the eninges performance dramatically.
Aug 12, 2005, 12:46 AM
Registered User sell something called an intelligent glow driver. It senses glow plug resistance at all throttle settings which helps preclude a cylinder dropping out. I use one on a Saito 90 twin with great results.
Aug 16, 2005, 04:58 PM
Registered User
ROUTIER's Avatar

New T6 flight with SAITO FA 100T

Hello friends,
Saturday the T6 have successfully fly without any engine problem and/or cylinder flame out .
Just before take off a check engine was done: it was running at 8600 rpm. Weather was windy and cross wind at about 10 knots. A short video have been posted on my website at (French page only at that time). But we have considerer that the power was just enough. Mainly I suppose that the choice of the new airscrew was not so good (14x8 instead of 14x6 at the maiden flight). I will try to test new type and propeller size. May be a 13x5 or 13x6 will be better giving more "punch" and a higher rpm to the engine.
Aug 16, 2005, 07:01 PM
Registered User
5% nitro is fine - my saito runs like clockwork on it and delivers the goods. Be very wary of lean runs with lower % of synthetic fuel - this can be risky.

FA 100 should be well capable of 14x8 prop, I'd say even more ... like a 15" or 16" should be no problem - what does the manufacturer recommend? Then go for the middle of this range

13x6 will be under propped for that engine - even if you consider that it's not making max power on the 5% nitro fuel (it's making close to max power)

A lengthy run in is necessary, starting very rich and gradually leaning out over a gallon of fuel - then run a little rich.

It might be the case that your motor isn't yet run in so be patient ... stick with the bigger prop and gradually lean out ... it'll get there

big bird
Aug 21, 2005, 02:28 AM
Registered User
ROUTIER's Avatar
Yesterday I have run the Saito again, burning 1 fuel liter. The engine was fited with a MA-K 13x5 and at full power I got 11.500 rpm. So That was a little bit too fast for this engine (The notice spoke about 10.300 max rpm).
I will try to find an intermediate propeller size like 13x10 or again 14x6 and run again 1 liter of fuel. It's true that I will always be carefuel to don't run the engine too lean!
Aug 22, 2005, 10:06 AM
S.A.D. member
ivanc's Avatar
13x10 is too fast of a prop. Better try with a 14x5 or 15x4. 14x6 might be OK too.
Jan 18, 2011, 08:02 AM
Registered User

Recommendations are for bigger props


14 x 8, 15 x4, 16 x 4 are the sizes for scale flying. It also sounds like you need to adjust the high and low speed needles and also balance the carbies. Possibly also adjust the carbypump flow.

the instructions are available off the net page 9 of the Saito twins section
Jan 18, 2011, 10:09 AM
Registered User
I TOBOR's Avatar
Rout, when you get the carbs set correctly that engine will run perfectly without any on board glow power and 5% will work well too. Saitos have great compression so high nitro is not necessary. That engine does not have a pump. Its best to set the engine up without any on board glow driver, the glow driver will cover up poor tuning and you'll have very poor fuel economy.
Last edited by I TOBOR; Jan 18, 2011 at 10:15 AM.
Jan 18, 2011, 04:42 PM
Registered User
Jim Kraft's Avatar
I would also add some oil, preferably castor, to bring it up to 20% total oil. The synthetic will keep the motor clean, and the castor will keep it lubed up. Castor won't burn like synthetic does, and will reach the cam and crank bearings better. Just my 2 cents.
Feb 19, 2011, 08:28 AM
Registered User

Castor oil in your 4 stroke Jim Kraft?

Never thought I'd hear someone to suggest castor added to fuel for a four stroke. Sure castor has it's place with hot running two strokes but not in four strokes with all those small moving parts. These engines run much slower and fuel is the coolant so don't lean it to the extreme. Castor oil, no thanks, I want my expensive four strokes running cool, strongly and smoothly for a long time.
Feb 20, 2011, 12:29 AM
Registered User
Remember ROUTIER is from France and they have better synthetic oil there. Their Synthetic oil all ester based. What we call synthetic cant be called synthetic in some other places.

But we get Nitro a lot cheaper.

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